Scheduling

It is possible to declare trigger statements in the evoke slot of a MLM.

An example would be:

…
data: an_event := EVENT{an event};;
evoke: an_event;;
logic: CONCLUDE TRUE;;
action: WRITE CURRENTTIME;;
…

This MLM would write the current time, when the event happens.

For the evoke slot, you may use:

• A blank evoke statement that implies the MLM can only be called:
  evoke: ;;

• Fixed dates or datetimes in ISO format:
  evoke: 1992-01-03T14:23:17.0;;

• Event variables declared in the data slot:
  evoke: an_event;;
evoke: an_event OR another_event;;
evoke: ANY OF(an_event, another_event);;

• Delayed triggers:
  evoke: 1 YEAR AFTER 2000-01-01;;
evoke: 15 SECONDS AFTER TIME OF an_event;;

• Cyclic triggers:
  evoke: EVERY 5 SECONDS FOR 2 WEEKS STARTING 2016-07-16T16:21:00;;
evoke: EVERY 5 SECONDS FOR 2 WEEKS STARTING TIME OF an_event;;
evoke: EVERY 5 SECONDS FOR 2 WEEKS STARTING TIME OF an_event UNTIL a_number > 5;;

• Various combinations:
  evoke: EVERY 5 SECONDS FOR 1 MINUTE STARTING 10 SECONDS AFTER TIME OF meh;;
evoke: EVERY 5 SECONDS FOR 2 WEEKS STARTING TIME OF (an_event OR another_event);;

Starting the Evoke Engine

You can start Arden2ByteCode with the -e or –engine option instead of -r or -c. This will start an engine that invokes the MLM on the desired schedule. It will listen for events indefinitely or until closed with ctrl+c.

The engine can be used together with the –port number option. This will start a server, that listens for event mapping strings on the given port.
To send an event to the server on port 9701 type (in Linux with Bash):

echo "Patient admission" > /dev/tcp/127.0.0.1/9701

Or connect via telnet:

telnet 127.0.0.1 9701